How to totally remove machine freezes on Aspire One 751 running Ubuntu 9.10
date=2010/02/14
kernel=Linux aspire1 2.6.31-17-generic #54-Ubuntu SMP Thu Dec 10 16:20:31 UTC 2009 i686 GNU/Linux

1. Upgrade BIOS to version 3211 at least
2. Upgrade Ubuntu to latest package versions (in particular the kernel, graphics (poulsbo) and sound drivers (snd-hda-intel))
3. edit /etc/modprobe.d/alsa-base.conf and ensure the following lines concerning snd-hda-intel remain commented :

…
# Power down HDA controllers after 10 idle seconds
options snd-hda-intel power_save=10 power_save_controller=N
options snd-hda-intel model=acer

You should obtain :

…
# Power down HDA controllers after 10 idle seconds
#options snd-hda-intel power_save=10 power_save_controller=N
#options snd-hda-intel model=acer

⇒ Now you should not experience random machine freeze anymore…

one good test to experience machine freeze (before following this procedure), is to listen to music through deezer.com
try this with unmodified alsa-base.conf Ubuntu or Windows XP that is shipped by Acer, it will freeze very quickly !!